So in my saga to figure out why my engine is suddenly sucking, I tested my AMM just now. the ohms are wavering b/t 3.3 and 3.2, which is under the 3.5 minimum. So does this mean that This could be the cause of all the issues? I sure hope so! When i unplugged the AMM, the idle stayed terrible, but as soon as i tried to move the throttle up at all, the car stalled. I'm new to AMM diagnostics, so if this means anything, someone please help me out! as usual, thanks a bunch
Nate Gundy
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'86 240DL, M46, K cam, 25/21mm sways

Be sure to plug-unplug your AMM with the ignition OFF. If you leave it on, you might damage an otherwise good AMM. And that would suck.

I'd guess that the slightly low resistamce readings are simply a meter calibration issue. What does your meter read when you touch the two probes together?
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Don Foster (near Cape Cod, MA)

well, i tested the AMM again now that the engine has been cooling for a couple hours, rather than 15 minutes. now it reads 3.1-3.2. my meter reads .4 to .3 when the probes are touching...does that mean i should subtract .4 or .3 from the reading? that would put me in the high 2's, which is definitely too low. does this make sense? oh, and i unplugged it with ignition off...thanks again
nate gundy
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'86 240DL, M46, K cam, 25/21mm sways

Generally, when measuring resistances below 15-20 ohms, you subtract the lead and probe contact resistance. (Obviously, if your measurements are thousands of ohms, then another half-ohm amounts to nothing.)

Your readings are a tad low. But before condemning the AMM, I'd make the same measurement on a different AMM (same type) for comparison.

I believe you're measuring the resistance of the platinum wire. It's hard to understand why its resistamce would drop (but not be zero) -- but easy to understand how it might go up or even be open (infinite).

Somewhere in my parts heaps, I have several AMM's from '85-'86 240s. I'll snoop and measure a few for you.
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Don Foster (near Cape Cod, MA)